East Kolkata Wetlands: Uncovering the Hidden Heroes of India's Water Treatment

Connecting the Dots: Tracing the History of the East Kolkata Wetlands KOLKATA, INDIA - The East Kolkata Wetlands, a 125-square-kilometer network of sewage-fed ponds, has been treating nearly 80% of the city's wastewater naturally for decades. According to environmental-humanities researcher Jenia Mukherjee, these wetlands recycle an astonishing 750 million liters of waste water daily and produce 22 tonnes of fish and 150 tonnes of vegetables. Mukherjee, who began her research on the region in 2007, used archival material to construct a 250-year history of the canal system. "When the British colonized India, they chose Kolkata as a site to develop," she explained. "The wetlands were an integral part of this development plan, designed to manage wastewater and provide a natural treatment system." The East Kolkata Wetlands are comprised of 254 sewage-fed ponds, each with its own unique dynamics in terms of size, ownership, and ecology. One such pond, owned by a cooperative where profits are shared equally among members, is home to a thriving ecosystem. "These wetlands are not just a natural wonder, but also a testament to the ingenuity of our ancestors," said Mukherjee. The ponds' ability to treat wastewater is due in part to the presence of water hyacinths (Pontederia crassipes), which absorb toxic metals and provide shelter for fish. However, having too many of these plants can harm the pond's ecosystem. "It's a delicate balance," noted Mukherjee. "We need to find ways to maintain this balance while also ensuring the long-term sustainability of the wetlands." The East Kolkata Wetlands have been recognized as a Ramsar site since 2002, acknowledging their importance as a natural habitat and water treatment system. However, despite its significance, the region faces numerous challenges, including encroachment by urban development and lack of adequate funding for maintenance. Mukherjee's research highlights the importance of preserving these wetlands not only for their ecological value but also for their potential to provide sustainable solutions for urban wastewater management. "The East Kolkata Wetlands are a model for other cities around the world," she said. "We can learn from their design and implementation, and apply these principles to develop more efficient and environmentally friendly wastewater treatment systems." As the city of Kolkata continues to grow and urbanize, the East Kolkata Wetlands remain a vital component of its infrastructure. By understanding and preserving this unique ecosystem, we can ensure a healthier and more sustainable future for generations to come. Background: The East Kolkata Wetlands were developed in the 18th century as part of the British colonial plan to manage wastewater from the city's growing population. The wetlands' design was influenced by traditional Indian water management systems, which utilized natural treatment processes to purify wastewater. Additional Perspectives: Dr. Sunita Narain, Director-General of the Centre for Science and Environment (CSE), noted that "the East Kolkata Wetlands are a shining example of how nature can be harnessed to solve urban environmental problems." She emphasized the need for more research and investment in sustainable wastewater management systems. Current Status and Next Developments: The East Kolkata Wetlands continue to face challenges related to encroachment, pollution, and inadequate funding. However, efforts are underway to preserve and restore these wetlands through community-led initiatives and government support. Mukherjee's research is being used as a model for developing more sustainable wastewater treatment systems in other cities around the world. Sources: Jenia Mukherjee, Environmental-Humanities Researcher, Indian Institute of Technology Kharagpur Dr. Sunita Narain, Director-General, Centre for Science and Environment (CSE) *Reporting by Nature.*